Understanding Directory Services  
   The companion site to "Understanding Directory Services", a book providing a technical explanation of directory service technologies. Includes information on X.500, LDAP, Active Directory, and Novell Directory Services.
   http://www.src.nu/uds

MaXware Enterprise Meta Solution  
   An enterprise-wide, vendor-independent solution that enables large end-user organizations and service providers to access, manage and maintain mission-critical data that is stored in different data repositories.
   http://www.maxware.com/

CNIDR IKnow  
   free java whois++ server
   http://www.cnidr.org/Iknow/Iknow.html

GANYMEDE: GASH 2  
   a portable and customizable directory management system.
   http://www.arlut.utexas.edu/gash2/

An LDAP Roadmap & FAQ  
   A tutorial aid to navigating various LDAP and X.500 resources on the Internet
   http://www.kingsmountain.com/ldapRoadmap.shtml

Internet Directory Consortium  
   composed of companies with a common interest in the implementation, testing, deployment and usage of directory (both LDAP and X.500) products in the market place.
   http://www.opengroup.org/idc/

NetVision  
   metadirectory product for integration of NDS, NT, and Notes, directories.
   http://www.netvision.com/

MessagingDirect  
   developers of standards based electronic messaging and directory software. The company provides E-commerce solutions based on secure embedded messaging.
   http://www.MessagingDirect.com/

Atlantic Media's AboutFace  
   employee directory products help consolidate disparate employee data information into one resource.
   http://www.aboutface.com

Linux NIS(YP) Server and Tools  
   The Network Information Service (NIS) provides a simple network lookup service consisting of databases and processes. It was formerly known as Sun Yellow Pages (YP).
   http://www.linux-nis.org/nis/